// 写串口程序
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <errno.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>
#include <stdlib.h>
#define BUFFER_SIZE 50

int set_opt(int fd, int nSpeed, int nBits, char nEvent, int nStop);
int open_port(int fd, int comport);

// 读串口程序
int main(void)
{
    int fd;
    char buff[BUFFER_SIZE];

    if((fd = open_port(fd, 1)) < 0){// 打开串口
        perror("open_port error");
        return -1;
    }
    if((set_opt(fd, 115200, 8, 'N', '1')) < 0){ //  设置串口
        perror("set_opt error");
        return -1;
    }
	do
	{
		memset(buff, 0, BUFFER_SIZE);
		if (read(fd, buff, BUFFER_SIZE) > 0)
		{
			printf("The received words are : %s", buff);
		}
	} while(strncmp(buff, "quit", 4));
    close(fd);
    return 1;
}



int set_opt(int fd, int nSpeed, int nBits, char nEvent, int nStop)
{
    struct termios newtio, oldtio;
    //保存测试现有串口参数设置，在这里如果串口号等出错，会有相关的出错信息
    if (tcgetattr(fd, &oldtio) != 0){
        perror("SetipSerial 1");
        return -1;
    }
    bzero(&newtio, sizeof(newtio));
    // 设置字符串大小
    newtio.c_cflag |= CLOCAL | CREAD;
    newtio.c_cflag &= ~CSIZE;
    // 设置停止位
    switch(nBits)
    {
        case 7:
            newtio.c_cflag |= CS7;
            break;
        case 8:
            newtio.c_cflag |= CS8;
            break;
    }
    switch(nEvent)
    {
        // 奇数
        case 'O':
            newtio.c_cflag |= PARENB;
            newtio.c_cflag |= PARODD;
            newtio.c_cflag |= (INPCK | ISTRIP);
            break;
        // 偶数
        case 'E':
            newtio.c_cflag |= (INPCK | ISTRIP);
            newtio.c_cflag |= PARENB;
            newtio.c_cflag &= ~PARODD;
            break;
        // 无奇偶校验位
        case 'N':
            newtio.c_cflag &= ~PARENB;
            break;
    }
    // 设置波特率
    switch (nSpeed)
    {
        case 2400:
            cfsetispeed(&newtio, B2400);
            cfsetospeed(&newtio, B2400);
            break;
        case 4800:
            cfsetispeed(&newtio, B4800);
            cfsetospeed(&newtio, B4800);
            break;
        case 9600:
            cfsetispeed(&newtio, B9600);
            cfsetospeed(&newtio, B9600);
            break;
        case 115200:
            cfsetispeed(&newtio, B115200);
            cfsetospeed(&newtio, B115200);
            break;
        case 460800:
            cfsetispeed(&newtio, B460800);
            cfsetospeed(&newtio, B460800);
            break;
        default:
            cfsetispeed(&newtio, B9600);
            cfsetospeed(&newtio, B9600);
            break;
    }
    // 设置停止位
    if(nStop == 1)
        newtio.c_cflag &= ~CSTOPB;
    else if ( nStop == 2 )
        newtio.c_cflag |= CSTOPB;
    // 设置等待时间和最小接收字符
    newtio.c_cc[VTIME] = 0;
    newtio.c_cc[VMIN] = 0;
    // 处理未接收字符
    tcflush(fd, TCIFLUSH);
    // 激活新配置
    if (( tcsetattr(fd, TCSANOW, &newtio)) != 0)
    {
        perror("com set error");
        return -1;
    }
    printf("set done!\n");
    return 0;
}

// 打开串口
int open_port(int fd, int comport)
{
    char *dev[] = {"/dev/ttyAMA0","/dev/ttyAMA1","/dev/ttyAMA2"};
    long vdisable;
    if (comport == 1)       // 串口1
    {
        fd = open("/dev/ttyAMA0",O_RDWR|O_NOCTTY|O_NDELAY);
        if ( -1 == fd){
            perror("Can,t Open Serial Port");
            return -1;
        }
    }
    if (comport == 2)       // 串口2
    {
        fd = open("/dev/ttyAMA1",O_RDWR|O_NOCTTY|O_NDELAY);
        if ( -1 == fd){
            perror("Can,t Open Serial Port");
            return -1;
        }
    }
    if (comport == 3)       // 串口3
    {
        fd = open("/dev/ttyAMA2",O_RDWR|O_NOCTTY|O_NDELAY);
        if ( -1 == fd){
            perror("Can,t Open Serial Port");
            return -1;
        }
    }
    // 恢复串口为阻塞状态
    if(fcntl(fd, F_SETFL, 0) < 0 )
        printf("fcntl failed!\n");
    else
        printf("fcntl = %d\n",fcntl(fd, F_SETFL, 0));
    //测试是否为终端设备
    if(isatty(STDIN_FILENO) == 0)
        printf("standard input is not a terminal device \n");
    else
        printf("isatty success!\n");
    printf("fd-open=%d\n",fd);
    return fd;
}